Widely adopted in recent years is an image processing system which with the interconnected devices of at least personal computers and digital complex devices establishes a network so as to allow data communications between these devices on the network. In such an image processing device, image data created on a personal computer and transmitted to a digital complex device on the network can be outputted to a recording medium such as a sheet of paper to obtain a finished record product, or the image data may be transmitted to other image processing devices.
Thus, by establishing a network between the personal computer and the image processing device, it is not required to exchange image data, for example, in the form of a record carrier such as a floppy disk between the image processing device and the personal computer. Further, since the image data can be transmitted or received on the network, image output can be controlled both easily and efficiently, for example, with the use of an intermediate information processing device such as a server.
Meanwhile, a network like this is usually required to meet various demand of users as flexibly as possible. Thus, control methods and control systems of image output used in such a network have been adapted to have a high flexibility. However, even such a network, depending on situations, sometimes requires control methods and control systems with a limited flexibility.
In light of this, there has been proposed, as disclosed in Japanese Unexamined Patent Publication No. 161823/1998 (Tokukaihei 10-161823) (published date: Jun. 19, 1998), a security management system which restricts image output based on whether the image data is security data or not in a common printer device (image forming device) on the network.
Specifically, in this security management system, restriction information such as the number of copies which can be made or available functions which are assigned to the image forming device, or the current status of the image forming device are stored in a database along with corresponding user ID information of each user using the image forming device. The use of the image forming device is either allowed or disallowed by a management device of the network based on the information stored in the database.
Further, Japanese Unexamined Patent Publication No. 157179/1999 (Tokukaihei 11-157179) (published date: Jun. 15, 1999) proposes a system which not only restricts the image forming device but restricts the use of an image forming device according to the content of output or the user, and flexibly changes restrictions.
More specifically, the image forming device in receipt of job data including predetermined processing procedures with the image data from a host computer establishes communications with an externally provided history management device according to this predetermined processing procedures, so as to control image output according to the result of this communication. Here, by changing the content of the predetermined processing procedures, restrictions on image output can be flexibly changed.
Incidentally, when the image forming system is in an environment where it is to be used for private purposes, the image data which the user wants as a finished record product needs to be outputted from the image forming device without any restrictions as he/she desires. However, when the image forming system is in a specific environment where the image data is used for specific purposes according to this environment, the image data does not necessarily reflect what the user wants.
For example, when the network is provided in an office, the image data should only relate to the business operations of this office. Thus, use of the image forming device by the user to output private image data which does not relate to business could violate the contract of employment because the user in this case is using the image forming device which should be used only for business purposes.
Further, use of the company's image forming device for purposes other than business purposes can lead to the problem of increased management cost because it consumes more expendables and increases the frequency of maintenance which is proportional to the frequency of use.
Such a problem becomes particularly prominent with the wide-spreading use of the Internet in these days, whereby the network of the image forming system is interconnected to the Internet via a server to allow users to obtain various ranges of image data from the Internet. Thus, the users can easily obtain image data of personal interests which does not relate to business off the Internet, which fosters private use of the image forming device.
This situation is not just the characteristic of print out of image data in the image forming device, but is also a characteristic of a scanner device which reads out images, and a communication device which sends image data. These devices can also be used to easily process image data of personal needs which does not relate to business, encouraging users to use these devices for private purposes.
Despite these drawbacks, the prior art does not take into consideration suppressing private use of business devices such as the image forming device itself. For example, the technique disclosed in the foregoing Tokukaihei 10-161823 is for security management and the publication is totally silent about structures or control methods for judging private use.
Further, the foregoing Tokukaihei 11-157179 discloses a structure which utilizes job data which includes predetermined processing procedures in addition to the image data. However, while it is theoretically possible to apply such job data for the purpose of suppressing private use of the image forming device, it increases data volume and complicates the control process. Thus, an efficient image forming system cannot be provided with this technique.
That is, the technique disclosed in Tokukaihei 11-157179 relates to an accounting process which works under the principle that image output is restricted, and it still easily allows private use of the image forming device and fails to realize an efficient image forming process in a system which restricts operations of the device.